[AAVSO-HEN] GRB 071112C: ROTSE-III Confirmation of Optical Counterpart

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  7061
SUBJECT: GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
DATE:    07/11/12 19:43:56 GMT
FROM:    Fang Yuan at ROTSE  <yuanfang at umich.edu>

F. Yuan (U Mich), E.S. Rykoff (UCSB), W. Rujopakarn (Steward), H. Swan 
(U Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 071112C (Swift trigger 296504; Perri, M. et. al., GCN 
7059). The first image was at 18:34:01.8 UT, 64.3 s after the burst 
(10.8 s after the GCN notice time). We detect the OT reported in GCN 
7059. The magnitude of the OT was roughly constant for the first few 
hundred seconds and then faded rapidly afterward. Further analysis is 
ongoing. The unfiltered images are calibrated relative to USNO B1.0.

Midtime UT       mag      magerror   mlim(of image)
--------------------------------------------------------------------
18:34:56.4   17.3       0.2     17.1
18:38:52.2   17.1       0.1     18.0
18:47:46.5   18.9       0.3     18.4


A jpeg image of the OT (object 82) is available at 
http://www.rotse.net/images/gsb296504_3c011-020_key.jpg

Continuing observations are in progress.